Problem: Simplify the following expression: $q = \dfrac{7n}{9} + \dfrac{n}{6}$
Solution: In order to add expressions, they must have a common denominator. The smallest common denominator is the least common multiple of $9$ and $6$ $\lcm(9, 6) = 18$ $ q = \dfrac{2}{2} \cdot \dfrac{7n}{9} + \dfrac{3}{3} \cdot \dfrac{n}{6} $ $q = \dfrac{14n}{18} + \dfrac{3n}{18}$ $q = \dfrac{14n +3n}{18}$ $q = \dfrac{17n}{18}$